It sounds like one of Rudyard Kipling’s Just So Stories, but how
the turtle got its shell is a tale of scientific sleuthing.

From lizards to armadillos, all other animals with body armour form it from
bony scales. However, turtles buck the trend, fusing ribs and vertebrae to
form a shell made up of about 50 bones. But just how and when this started
to happen has had palaeontologists scratching their heads for years.

Now scientists have discovered crucial evidence from fossils of a bizarre
creature known as Eunotosaurus,
the earliest known turtle ancestor, which lived 260 million years ago.